Adhesion molecules expressed on control erythrocytes made artificially PS-positive and on erythrocytes from patients with sickle cell disease
| Marker . | . | Erythrocytes from control donors . | Erythrocytes from patients with sickle cell disease . | ||
|---|---|---|---|---|---|
| Untreated (n = 4) . | *A23187-treated erythrocytes diluted with untreated RBCs (n = 4) . | †Low PS group (n = 4) . | †High PS group (n = 5) . | ||
| CD36 | Positivity | Not present | Not present | 0.5 ± 0.5% | 1.4 ± 1.7% |
| VLA4 | Positivity | Not present | Not present | 0.03 ± 0.06% | 0.03 ± 0.06% |
| PS | Positivity | < 0.3% | 15% | 1.0 ± 0.8% | ††7.0 ± 2.8% |
| CD47 (IAP) | Positivity; MCF | 100%; 629 ± 15 | 100%; 630 ± 5 | 99 ± 1%; 698 ± 52 | 99 ± 1%; 721 ± 41 |
| CD239 (BCAM/LU) | Positivity; MCF | 23 ± 16%; 305 ± 47 | 20 ± 13%; 300 ± 32 | 44 ± 9%; 414 ± 12 | 21 ± 16%; 389 ± 79 |
| Marker . | . | Erythrocytes from control donors . | Erythrocytes from patients with sickle cell disease . | ||
|---|---|---|---|---|---|
| Untreated (n = 4) . | *A23187-treated erythrocytes diluted with untreated RBCs (n = 4) . | †Low PS group (n = 4) . | †High PS group (n = 5) . | ||
| CD36 | Positivity | Not present | Not present | 0.5 ± 0.5% | 1.4 ± 1.7% |
| VLA4 | Positivity | Not present | Not present | 0.03 ± 0.06% | 0.03 ± 0.06% |
| PS | Positivity | < 0.3% | 15% | 1.0 ± 0.8% | ††7.0 ± 2.8% |
| CD47 (IAP) | Positivity; MCF | 100%; 629 ± 15 | 100%; 630 ± 5 | 99 ± 1%; 698 ± 52 | 99 ± 1%; 721 ± 41 |
| CD239 (BCAM/LU) | Positivity; MCF | 23 ± 16%; 305 ± 47 | 20 ± 13%; 300 ± 32 | 44 ± 9%; 414 ± 12 | 21 ± 16%; 389 ± 79 |
Cell-surface PS and other potential erythrocyte adhesion markers were evaluated using 2-color flow cytometry and employing anti-glycophorin A as a marker for red cells. Values presented are the mean (± SD). Mean cell fluorescence (MCF) is a measure of receptor density per cell. Changes (positivity or MCF) noted with CD47 or CD239 between the control and A23187-treated erythrocyte were not significantly different from each other. The “low” PS sickle cell group is compared with the “high” PS sickle cell group to demonstrate that the adhesion marker differences between these two HbSS groups was confined to significant differences in PS positivity.
IAP indicates integrin associated protein; and BCAM/LU, basal cell adhesion molecule/Lutheran protein.
PS-positive red cells were prepared by treating control HbAA erythrocytes with A23187 and diluted with untreated red cells to obtain a cell suspension containing 15% PS positivity.
Erythrocytes from patients with sickle cell disease (HbSS genotype) were divided into 2 experimental groups including low PS and high PS groups based on percent PS positivity as in our previous study.5
P < .02 compared to low PS group.